• Proceedings of the Korea Concrete Institute Conference
• /
• 2001.05a
• /
• pp.751-756
• /
• 2001

Permanent-Form is one of system forms for reducing human labor, work costs, oscillation, noise, construction wastes and so on. Permanent-Form is made from precast method in facilities. and carried in construction site to assemble with no demolding. The biggest expense to produce Permanent-Form is about manufacturing mold. To satisfy various size of building member, the same number of manufacturing mold is needed. In this paper, studied about manufacturing mold module for acquiring economic merit and construction member safety. Permanent-Form is member stress and structural analyzed if temporary equipment were used. The result of this study is below. (1) Column sizes of Permanent-Form are 47 kinds of prototype that based on Modular coordination's basic module. 4 pieces or 6 pieces are composed basically. (2) For beam size modular coordination, standard height and width of beam are 150mm and 100mm. It brings 24 kinds of prototype. 4 pieces or 5 pieces are composed basically. (3) Structural analysis value of modular member is like this Column member shows 9.4 to 85kgf/$cm^{2}$ stress distribution and beam member shows 6.3 to 95kgf/$cm^{2}$ stress distribution. Constructing permanent form could have structural safety with use of temporary equipment

• Journal of the Korean Society of Safety
• /
• v.35 no.4
• /
• pp.15-22
• /
• 2020

Scaffolding works are demolished after this structure is completed, and safety accidents often occur because they are installed differently from legal standards or frequently change during work. Therefore, in order to strengthen the safety of scaffolding, the Ministry of Land, Infrastructure and Transport required a need for design standards for temporary facilities that can systematically prevent and solve large-scale safety accidents that are repeatedly increasing during temporary construction. It has been enacted, and some contents have been revised for the past three years. However, construction site personnel do not know or know the revised matters, but often install scaffolding by the installer's experience rather than complying with relevant laws and regulations. It is the situation that the ground strength test of the foundation ground for the load applied to the floor of the column is omitted in most sites. Therefore, this study grasped the actual situation on the degree of recognition of the revised laws and regulations of the construction site and the foundation-based treatment of the floor working load of the scaffolding column, and derived problems. In addition, we intend to provide reference materials for the endurance test according to the ground conditions to small-scale small sites where it is difficult to conduct the test by carrying out the endurance test of the scaffolding ground according to the revised standards.

• Korean Journal of Human Ecology
• /
• v.17 no.5
• /
• pp.939-950
• /
• 2008

The purposes of this study are 1) to investigate the employment status of the elderly(i.e., whether the elderly is employed or not) in Ulsan, 2) to analyze the differences in household economic life between employed and unemployed old People, and 3) only for the employed old people, to compare the monthly earnings and job satisfaction by the work time of per day and by the regular employee or temporary employee. for this study, semi-structural questionnaires were distributed to 500 old people in Ulsan, in September, 2006. The results indicated that only 25% of the respondents were employed, and the employment status of the elderly was related to sex, age, education level, marital status, household composition, number of dwelling persons, and number of children. for household economic life, employed old people had higher household income and monthly allowances than unemployed old people, while they spent more on clothing, but less on food than unemployed old people. Regular old employees had higher monthly earnings and job satisfaction than temporary old employees. And the old employees working for more than 8 hours per day had higher monthly earnings than those working for less than 8 hours, but there was no significant difference in job satisfaction between the two groups.

• Journal of the Korean Institute of Rural Architecture
• /
• v.8 no.2
• /
• pp.80-93
• /
• 2006

This purpose was to explore various directions of elderly service welfare space in village community center. Data were collected 3 types that floor plans of village community centers from 24 villages, interview data of these centers use and needs from 24 aged leaders or 96 elderly. The results were as followed: 1) The floor plans of more than 50% was type IV that was composed a basic spaces(entrance, living room, two rooms, kitchen), a toilet space, a heating system space and a storage space. This type was a current basis of the rural village community centers for elderlies. 2) Elderlies used the centers at winter or out of agricultural season, and visited these to pass the time and to promote friendship among them. 3) Also they went these to take a meal together and to save down personal heating expenses. Their needs for centers were a temporary share dwelling space at winter, a maintain social relationship throughout a health, a education and a side work activity, supplying health or sports facilities, and setting up toilet space. Therefore the current centers were needed to add functions of a temporary share dwelling, a energy saving heat system and a social promoting relationship, and so these could be represented to a elderly welfare service center in rural villages.

• Journal of Information Processing Systems
• /
• v.16 no.3
• /
• pp.588-598
• /
• 2020

An alternative state estimation filtering algorithm is designed for continuous time systems with noises as well as control input. Two kinds of estimation filters, which have different measurement memory structures, are operated selectively in order to use both filters effectively as needed. Firstly, the estimation filter with infinite memory structure is operated for a certain continuous time system. Secondly, the estimation filter with finite memory structure is operated for temporarily uncertain continuous time system. That is, depending on the presence of uncertainty, one of infinite memory structure and finite memory structure filtered estimates is operated selectively to obtain the valid estimate. A couple of test variables and declaration rule are developed to detect uncertainty presence or uncertainty absence, to operate the suitable one from two kinds of filtered estimates, and to obtain ultimately the valid filtered estimate. Through computer simulations for a continuous time aircraft engine system with different measurement memory lengths and temporary model uncertainties, the proposed state estimation filtering algorithm can work well in temporarily uncertain as well as certain continuous time systems. Moreover, the proposed state estimation filtering algorithm shows remarkable superiority to the infinite memory structure filtering when temporary uncertainties occur in succession.

• Journal of the Ergonomics Society of Korea
• /
• v.29 no.5
• /
• pp.751-762
• /
• 2010

The purpose of this study was to investigate the job stress factors of aircraft composite material part manufacturing workers using survey based on 'Job stress factors evaluation tool for Koreans' that was developed by KOSHA in 2003. Two hundred and fifty workers participated in this study, and among them 204 responses were analyzed for this study due to the unreliability and insincerity of responses. The eight job stress factors which are physical environment, job autonomy, job insecurity, organizational system, workplace culture, unfair compensation, relationship conflict, and job requirement were analyzed. The results showed that the stress level of the six job stress factors which are physical environment, job autonomy, job insecurity, organizational system, workplace culture, unfair compensation was relatively higher than that of other industry workers. Generally, all eight job stress factors showed higher stress with temporary workers than with permanent workers, and especially job autonomy, job insecurity, organizational system, and unfair compensation factors showed statistically significant differences (p<0.05). Since the temporary workers are insecure with their job, weak position in organization, having little self-control for the job and lower pay level than that of permanent workers though the job is as same as permanent workers', the stress level of above job stress factors would be much higher than that of the other factors. The group of unsatisfactory with workplace showed higher job stress than group of satisfactory with workplace in all job stress factors, as expected, at the statistically significance level (p<0.05). From the results of this study, the work loss due to the job stress could be prevented, and accurate stress factors could be removed at the workplace. Also the job stress management program can be implemented to improve the work efficiency and the workers' quality of life.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2010.09a
• /
• pp.124-143
• /
• 2010

Cofferdam is a temporary levee or dam structure built by using sheet pile or earth materials to prevent water infiltration during construction work of bridge, dam, harbour dock, or hydraulic structures in the river. In this regard, it is required to secure cutoff ability for dry work and workability for rapid installation and removal of the temporary dam or levee structures. In this paper, case studies for design and construction of cofferdam were performed, and water diversion method was briefed with some examples of cofferdam type as well. For the case study details of design and construction were reviewed based on cofferdams under construction related to 16 submerged weirs of "The 4-river restoration project" and dam type cofferdam respectively. From the review, it was known that the method for changing the water flow is selected based on the data from geological and geo-hydraulic site investigation in order to mitigate environmental effects by making sure if the design cross-sectional area of flow and maximum working days are sufficiently guaranteed. Finally, the primary findings and main conclusion derived are summarized that determination of applicable type of cofferdam should be checked by case study and meet design requirements such as water inflow control, constructability.

• Journal of Korean society of Dental Hygiene
• /
• v.13 no.6
• /
• pp.1005-1014
• /
• 2013

Objectives : The purpose of the study is to obtain the basic data for an industrial oral health project enhancing the quality of life and oral health. Methods : Questionnaire consisted of 17 questions including 7 questions of general characteristics, 5 questions of oral health awareness, and 5 questions of the behavior of oral health. A self-reported questionnaire was carried out from September 1 to September 28, 2012, The subjects were 400 male and female sanitation workers in private corporations in Jeonju. A total of 354 questionnaires were analyzed using SPSS windows ver. 12.0 (SPSS Inc. Korea). Results : The majority of the subjects were male in 50's. Temporary contract workers are older aged and 2 to 5 years of career workers were the majority of the cleaners. Average monthly income was less than 2 million Korean Won. Those who had a higher academic background and permanent position tended to have oral health knowledge (p<0.05). Female workers had healthier subjective oral health status than male workers. Those who were in older age, single, temporary position, and 2 to 5 years of career tended to have healthier subjective oral health status (p<0.05). Those who were in older age, married, and long period of employment were worrying about their health (p<0.05). The subjective oral health knowledge was high in 49.7% of the workers because they were not able to brush teeth during work hours. They were able to brush their teeth only after dinner. It was low in female and older aged workers (p<0.05). The brushing method included a combination of top to bottom and from the side to side. Conclusions : This study showed the influencing factor of oral health in street workers. Work environment, education, age, monthly income, and types of employment were the important factors to oral health care. It is necessary to provide the right oral health care program for the workers in the near future.

• Journal of dental hygiene science
• /
• v.18 no.3
• /
• pp.155-163
• /
• 2018

This study's aim was to investigate their opinions to improve the educational system for dental hygienists on the basis of their duties as dental hygienists. The qualitative study was conducted among 19 dental hygienists at Daejeon, Korea from July to August 2016. Two researchers followed each subject for working hours in a day and recorded all the tasks and time to take for each task. After one day, the researchers met each subject and conducted face-to-face interviews to investigate the opinions about the dental hygiene curriculum and national board examination. The main duties recognized by more than half of the subjects were oral disease prevention including scaling and dental treatment assistance. The subjects' minority opinion about the main duties included radiography, impression taking, dental implant surgery assistance, orthodontic treatment, patient counseling, dental management and staff management, and oral health education. The most important tasks perceived by the subjects were prosthetic and implant impressions, scaling and implant surgery assistance. The subjects' minority opinion about the most important duties included patient counseling and making temporary crowns. The most difficult tasks answered by the subjects were prosthetic and implant impressions and dental implant surgery assistance. The subjects' minority opinion about it included patient counseling, scaling, and making temporary crowns. They mentioned that their curriculum in college was different from the actual work and the national board examination was not reflective of their real duties. We found out Korean dental hygienists had a lot of roles as dental assistants, dental business managers, and so on. We suggest that the law, curriculum and national board examination for dental hygienists should be revised to be able to reflect the reality of the clinical field.

• Journal of the Korea Institute of Construction Safety
• /
• v.2 no.1
• /
• pp.9-15
• /
• 2019

Despite the efforts for enhancing the safety record, construction industry has been suffered from higher fatalities than other industries. The poor record of safety in construction industry means that there is a clear need for an effective countermeasure. As mentioned in previous studies, it is important to identify the type of activities or risks that are likely to cause accidents and to develop appropriate safety measures. Considering the large number of accident cases on the temporary installations including work platforms and work passages, the temporary installations should be managed first. To support it, this study aims to analyze falling accident cases on construction working platforms and passages which can lead to develop proper safety measures. Through the analysis of 1663 accident cases in the perspective of cost, progress, activity, and type of workers, this study identifies how the recent accidents occur and what is the cause of the accident occurrence. The identified causes of accident occurrence will help us to improve current construction safety.